1 //===-- StopInfo.cpp ---------------------------------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "lldb/lldb-python.h"
11 
12 #include "lldb/Target/StopInfo.h"
13 
14 // C Includes
15 // C++ Includes
16 #include <string>
17 
18 // Other libraries and framework includes
19 // Project includes
20 #include "lldb/Core/Log.h"
21 #include "lldb/Breakpoint/Breakpoint.h"
22 #include "lldb/Breakpoint/BreakpointLocation.h"
23 #include "lldb/Breakpoint/StoppointCallbackContext.h"
24 #include "lldb/Breakpoint/Watchpoint.h"
25 #include "lldb/Core/Debugger.h"
26 #include "lldb/Core/StreamString.h"
27 #include "lldb/Core/ValueObject.h"
28 #include "lldb/Expression/ClangUserExpression.h"
29 #include "lldb/Target/Target.h"
30 #include "lldb/Target/Thread.h"
31 #include "lldb/Target/ThreadPlan.h"
32 #include "lldb/Target/Process.h"
33 #include "lldb/Target/UnixSignals.h"
34 
35 using namespace lldb;
36 using namespace lldb_private;
37 
38 StopInfo::StopInfo (Thread &thread, uint64_t value) :
39     m_thread_wp (thread.shared_from_this()),
40     m_stop_id (thread.GetProcess()->GetStopID()),
41     m_resume_id (thread.GetProcess()->GetResumeID()),
42     m_value (value),
43     m_override_should_notify (eLazyBoolCalculate),
44     m_override_should_stop (eLazyBoolCalculate),
45     m_extended_info()
46 {
47 }
48 
49 bool
50 StopInfo::IsValid () const
51 {
52     ThreadSP thread_sp (m_thread_wp.lock());
53     if (thread_sp)
54         return thread_sp->GetProcess()->GetStopID() == m_stop_id;
55     return false;
56 }
57 
58 void
59 StopInfo::MakeStopInfoValid ()
60 {
61     ThreadSP thread_sp (m_thread_wp.lock());
62     if (thread_sp)
63     {
64         m_stop_id = thread_sp->GetProcess()->GetStopID();
65         m_resume_id = thread_sp->GetProcess()->GetResumeID();
66     }
67 }
68 
69 bool
70 StopInfo::HasTargetRunSinceMe ()
71 {
72     ThreadSP thread_sp (m_thread_wp.lock());
73 
74     if (thread_sp)
75     {
76         lldb::StateType ret_type = thread_sp->GetProcess()->GetPrivateState();
77         if (ret_type == eStateRunning)
78         {
79             return true;
80         }
81         else if (ret_type == eStateStopped)
82         {
83             // This is a little tricky.  We want to count "run and stopped again before you could
84             // ask this question as a "TRUE" answer to HasTargetRunSinceMe.  But we don't want to
85             // include any running of the target done for expressions.  So we track both resumes,
86             // and resumes caused by expressions, and check if there are any resumes NOT caused
87             // by expressions.
88 
89             uint32_t curr_resume_id = thread_sp->GetProcess()->GetResumeID();
90             uint32_t last_user_expression_id = thread_sp->GetProcess()->GetLastUserExpressionResumeID ();
91             if (curr_resume_id == m_resume_id)
92             {
93                 return false;
94             }
95             else if (curr_resume_id > last_user_expression_id)
96             {
97                 return true;
98             }
99         }
100     }
101     return false;
102 }
103 
104 //----------------------------------------------------------------------
105 // StopInfoBreakpoint
106 //----------------------------------------------------------------------
107 
108 namespace lldb_private
109 {
110 class StopInfoBreakpoint : public StopInfo
111 {
112 public:
113     StopInfoBreakpoint (Thread &thread, break_id_t break_id) :
114         StopInfo (thread, break_id),
115         m_description(),
116         m_should_stop (false),
117         m_should_stop_is_valid (false),
118         m_should_perform_action (true),
119         m_address (LLDB_INVALID_ADDRESS),
120         m_break_id(LLDB_INVALID_BREAK_ID),
121         m_was_one_shot (false)
122     {
123         StoreBPInfo();
124     }
125 
126     StopInfoBreakpoint (Thread &thread, break_id_t break_id, bool should_stop) :
127         StopInfo (thread, break_id),
128         m_description(),
129         m_should_stop (should_stop),
130         m_should_stop_is_valid (true),
131         m_should_perform_action (true),
132         m_address (LLDB_INVALID_ADDRESS),
133         m_break_id(LLDB_INVALID_BREAK_ID),
134         m_was_one_shot (false)
135     {
136         StoreBPInfo();
137     }
138 
139     void
140     StoreBPInfo ()
141     {
142         ThreadSP thread_sp (m_thread_wp.lock());
143         if (thread_sp)
144         {
145             BreakpointSiteSP bp_site_sp (thread_sp->GetProcess()->GetBreakpointSiteList().FindByID (m_value));
146             if (bp_site_sp)
147             {
148                 if (bp_site_sp->GetNumberOfOwners() == 1)
149                 {
150                     BreakpointLocationSP bp_loc_sp = bp_site_sp->GetOwnerAtIndex(0);
151                     if (bp_loc_sp)
152                     {
153                         m_break_id = bp_loc_sp->GetBreakpoint().GetID();
154                         m_was_one_shot = bp_loc_sp->GetBreakpoint().IsOneShot();
155                     }
156                 }
157                 m_address = bp_site_sp->GetLoadAddress();
158             }
159         }
160     }
161 
162     virtual ~StopInfoBreakpoint ()
163     {
164     }
165 
166     virtual bool
167     IsValidForOperatingSystemThread (Thread &thread)
168     {
169         ProcessSP process_sp (thread.GetProcess());
170         if (process_sp)
171         {
172             BreakpointSiteSP bp_site_sp (process_sp->GetBreakpointSiteList().FindByID (m_value));
173             if (bp_site_sp)
174                 return bp_site_sp->ValidForThisThread (&thread);
175         }
176         return false;
177     }
178 
179     virtual StopReason
180     GetStopReason () const
181     {
182         return eStopReasonBreakpoint;
183     }
184 
185     virtual bool
186     ShouldStopSynchronous (Event *event_ptr)
187     {
188         ThreadSP thread_sp (m_thread_wp.lock());
189         if (thread_sp)
190         {
191             if (!m_should_stop_is_valid)
192             {
193                 // Only check once if we should stop at a breakpoint
194                 BreakpointSiteSP bp_site_sp (thread_sp->GetProcess()->GetBreakpointSiteList().FindByID (m_value));
195                 if (bp_site_sp)
196                 {
197                     ExecutionContext exe_ctx (thread_sp->GetStackFrameAtIndex(0));
198                     StoppointCallbackContext context (event_ptr, exe_ctx, true);
199                     bp_site_sp->BumpHitCounts();
200                     m_should_stop = bp_site_sp->ShouldStop (&context);
201                 }
202                 else
203                 {
204                     Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
205 
206                     if (log)
207                         log->Printf ("Process::%s could not find breakpoint site id: %" PRId64 "...", __FUNCTION__, m_value);
208 
209                     m_should_stop = true;
210                 }
211                 m_should_stop_is_valid = true;
212             }
213             return m_should_stop;
214         }
215         return false;
216     }
217 
218     virtual bool
219     DoShouldNotify (Event *event_ptr)
220     {
221         ThreadSP thread_sp (m_thread_wp.lock());
222         if (thread_sp)
223         {
224             BreakpointSiteSP bp_site_sp (thread_sp->GetProcess()->GetBreakpointSiteList().FindByID (m_value));
225             if (bp_site_sp)
226             {
227                 bool all_internal = true;
228 
229                 for (uint32_t i = 0; i < bp_site_sp->GetNumberOfOwners(); i++)
230                 {
231                     if (!bp_site_sp->GetOwnerAtIndex(i)->GetBreakpoint().IsInternal())
232                     {
233                         all_internal = false;
234                         break;
235                     }
236                 }
237                 return all_internal == false;
238             }
239         }
240         return true;
241     }
242 
243     virtual const char *
244     GetDescription ()
245     {
246         if (m_description.empty())
247         {
248             ThreadSP thread_sp (m_thread_wp.lock());
249             if (thread_sp)
250             {
251                 BreakpointSiteSP bp_site_sp (thread_sp->GetProcess()->GetBreakpointSiteList().FindByID (m_value));
252                 if (bp_site_sp)
253                 {
254                     StreamString strm;
255                     // If we have just hit an internal breakpoint, and it has a kind description, print that instead of the
256                     // full breakpoint printing:
257                     if (bp_site_sp->IsInternal())
258                     {
259                         size_t num_owners = bp_site_sp->GetNumberOfOwners();
260                         for (size_t idx = 0; idx < num_owners; idx++)
261                         {
262                             const char *kind = bp_site_sp->GetOwnerAtIndex(idx)->GetBreakpoint().GetBreakpointKind();
263                             if (kind != NULL)
264                             {
265                                 m_description.assign (kind);
266                                 return kind;
267                             }
268                         }
269                     }
270 
271                     strm.Printf("breakpoint ");
272                     bp_site_sp->GetDescription(&strm, eDescriptionLevelBrief);
273                     m_description.swap (strm.GetString());
274                 }
275                 else
276                 {
277                     StreamString strm;
278                     if (m_break_id != LLDB_INVALID_BREAK_ID)
279                     {
280                         BreakpointSP break_sp = thread_sp->GetProcess()->GetTarget().GetBreakpointByID(m_break_id);
281                         if (break_sp)
282                         {
283                             if (break_sp->IsInternal())
284                             {
285                                 const char *kind = break_sp->GetBreakpointKind();
286                                 if (kind)
287                                     strm.Printf ("internal %s breakpoint(%d).", kind, m_break_id);
288                                 else
289                                     strm.Printf ("internal breakpoint(%d).", m_break_id);
290                             }
291                             else
292                             {
293                                 strm.Printf ("breakpoint %d.", m_break_id);
294                             }
295                         }
296                         else
297                         {
298                             if (m_was_one_shot)
299                                 strm.Printf ("one-shot breakpoint %d", m_break_id);
300                             else
301                                 strm.Printf ("breakpoint %d which has been deleted.", m_break_id);
302                         }
303                     }
304                     else if (m_address == LLDB_INVALID_ADDRESS)
305                         strm.Printf("breakpoint site %" PRIi64 " which has been deleted - unknown address", m_value);
306                     else
307                         strm.Printf("breakpoint site %" PRIi64 " which has been deleted - was at 0x%" PRIx64, m_value, m_address);
308 
309                     m_description.swap (strm.GetString());
310                 }
311             }
312         }
313         return m_description.c_str();
314     }
315 
316 protected:
317     bool
318     ShouldStop (Event *event_ptr)
319     {
320         // This just reports the work done by PerformAction or the synchronous stop.  It should
321         // only ever get called after they have had a chance to run.
322         assert (m_should_stop_is_valid);
323         return m_should_stop;
324     }
325 
326     virtual void
327     PerformAction (Event *event_ptr)
328     {
329         if (!m_should_perform_action)
330             return;
331         m_should_perform_action = false;
332 
333         ThreadSP thread_sp (m_thread_wp.lock());
334 
335         if (thread_sp)
336         {
337             Log *log = lldb_private::GetLogIfAnyCategoriesSet (LIBLLDB_LOG_BREAKPOINTS | LIBLLDB_LOG_STEP);
338 
339             if (!thread_sp->IsValid())
340             {
341                 // This shouldn't ever happen, but just in case, don't do more harm.
342                 if (log)
343                 {
344                     log->Printf ("PerformAction got called with an invalid thread.");
345                 }
346                 m_should_stop = true;
347                 m_should_stop_is_valid = true;
348                 return;
349             }
350 
351             BreakpointSiteSP bp_site_sp (thread_sp->GetProcess()->GetBreakpointSiteList().FindByID (m_value));
352             std::unordered_set<break_id_t> precondition_breakpoints;
353 
354             if (bp_site_sp)
355             {
356                 size_t num_owners = bp_site_sp->GetNumberOfOwners();
357 
358                 if (num_owners == 0)
359                 {
360                     m_should_stop = true;
361                 }
362                 else
363                 {
364                     // We go through each location, and test first its precondition - this overrides everything.  Note,
365                     // we only do this once per breakpoint - not once per location...
366                     // Then check the condition.  If the condition says to stop,
367                     // then we run the callback for that location.  If that callback says to stop as well, then
368                     // we set m_should_stop to true; we are going to stop.
369                     // But we still want to give all the breakpoints whose conditions say we are going to stop a
370                     // chance to run their callbacks.
371                     // Of course if any callback restarts the target by putting "continue" in the callback, then
372                     // we're going to restart, without running the rest of the callbacks.  And in this case we will
373                     // end up not stopping even if another location said we should stop.  But that's better than not
374                     // running all the callbacks.
375 
376                     m_should_stop = false;
377 
378                     ExecutionContext exe_ctx (thread_sp->GetStackFrameAtIndex(0));
379                     Process *process  = exe_ctx.GetProcessPtr();
380                     if (process->GetModIDRef().IsLastResumeForUserExpression())
381                     {
382                         // If we are in the middle of evaluating an expression, don't run asynchronous breakpoint commands or
383                         // expressions.  That could lead to infinite recursion if the command or condition re-calls the function
384                         // with this breakpoint.
385                         // TODO: We can keep a list of the breakpoints we've seen while running expressions in the nested
386                         // PerformAction calls that can arise when the action runs a function that hits another breakpoint,
387                         // and only stop running commands when we see the same breakpoint hit a second time.
388 
389                         m_should_stop_is_valid = true;
390                         if (log)
391                             log->Printf ("StopInfoBreakpoint::PerformAction - Hit a breakpoint while running an expression,"
392                                          " not running commands to avoid recursion.");
393                         bool ignoring_breakpoints = process->GetIgnoreBreakpointsInExpressions();
394                         if (ignoring_breakpoints)
395                         {
396                             m_should_stop = false;
397                             // Internal breakpoints will always stop.
398                             for (size_t j = 0; j < num_owners; j++)
399                             {
400                                 lldb::BreakpointLocationSP bp_loc_sp = bp_site_sp->GetOwnerAtIndex(j);
401                                 if (bp_loc_sp->GetBreakpoint().IsInternal())
402                                 {
403                                     m_should_stop = true;
404                                     break;
405                                 }
406                             }
407                         }
408                         else
409                         {
410                             m_should_stop = true;
411                         }
412                         if (log)
413                             log->Printf ("StopInfoBreakpoint::PerformAction - in expression, continuing: %s.",
414                                          m_should_stop ? "true" : "false");
415                         process->GetTarget().GetDebugger().GetAsyncOutputStream()->Printf("Warning: hit breakpoint while "
416                                                "running function, skipping commands and conditions to prevent recursion.");
417                         return;
418                     }
419 
420                     StoppointCallbackContext context (event_ptr, exe_ctx, false);
421 
422                     // Let's copy the breakpoint locations out of the site and store them in a local list.  That way if
423                     // one of the breakpoint actions changes the site, then we won't be operating on a bad list.
424                     // For safety's sake let's also grab an extra reference to the breakpoint owners of the locations we're
425                     // going to examine, since the locations are going to have to get back to their breakpoints, and the
426                     // locations don't keep their owners alive.  I'm just sticking the BreakpointSP's in a vector since
427                     // I'm only really using it to locally increment their retain counts.
428 
429                     BreakpointLocationCollection site_locations;
430                     std::vector<lldb::BreakpointSP> location_owners;
431 
432                     for (size_t j = 0; j < num_owners; j++)
433                     {
434                         BreakpointLocationSP loc(bp_site_sp->GetOwnerAtIndex(j));
435                         site_locations.Add(loc);
436                         location_owners.push_back(loc->GetBreakpoint().shared_from_this());
437 
438                     }
439 
440                     for (size_t j = 0; j < num_owners; j++)
441                     {
442                         lldb::BreakpointLocationSP bp_loc_sp = site_locations.GetByIndex(j);
443 
444                         // If another action disabled this breakpoint or its location, then don't run the actions.
445                         if (!bp_loc_sp->IsEnabled() || !bp_loc_sp->GetBreakpoint().IsEnabled())
446                             continue;
447 
448                         // The breakpoint site may have many locations associated with it, not all of them valid for
449                         // this thread.  Skip the ones that aren't:
450                         if (!bp_loc_sp->ValidForThisThread(thread_sp.get()))
451                         {
452                             if (log)
453                             {
454                                 StreamString s;
455                                 bp_loc_sp->GetDescription(&s, eDescriptionLevelBrief);
456                                 log->Printf ("Breakpoint %s hit on thread 0x%llx but it was not for this thread, continuing.",
457                                              s.GetData(),
458                                              static_cast<unsigned long long>(thread_sp->GetID()));
459                             }
460                             continue;
461                         }
462 
463                         // First run the precondition, but since the precondition is per breakpoint, only run it once
464                         // per breakpoint.
465                         std::pair<std::unordered_set<break_id_t>::iterator, bool> result
466                                 = precondition_breakpoints.insert(bp_loc_sp->GetBreakpoint().GetID());
467                         if (!result.second)
468                             continue;
469 
470                         bool precondition_result = bp_loc_sp->GetBreakpoint().EvaluatePrecondition(context);
471                         if (!precondition_result)
472                             continue;
473 
474                         // Next run the condition for the breakpoint.  If that says we should stop, then we'll run
475                         // the callback for the breakpoint.  If the callback says we shouldn't stop that will win.
476 
477                         if (bp_loc_sp->GetConditionText() != NULL)
478                         {
479                             Error condition_error;
480                             bool condition_says_stop = bp_loc_sp->ConditionSaysStop(exe_ctx, condition_error);
481 
482                             if (!condition_error.Success())
483                             {
484                                 Debugger &debugger = exe_ctx.GetTargetRef().GetDebugger();
485                                 StreamSP error_sp = debugger.GetAsyncErrorStream ();
486                                 error_sp->Printf ("Stopped due to an error evaluating condition of breakpoint ");
487                                 bp_loc_sp->GetDescription (error_sp.get(), eDescriptionLevelBrief);
488                                 error_sp->Printf (": \"%s\"",
489                                                   bp_loc_sp->GetConditionText());
490                                 error_sp->EOL();
491                                 const char *err_str = condition_error.AsCString("<Unknown Error>");
492                                 if (log)
493                                     log->Printf("Error evaluating condition: \"%s\"\n", err_str);
494 
495                                 error_sp->PutCString (err_str);
496                                 error_sp->EOL();
497                                 error_sp->Flush();
498                             }
499                             else
500                             {
501                                 if (log)
502                                 {
503                                     StreamString s;
504                                     bp_loc_sp->GetDescription(&s, eDescriptionLevelBrief);
505                                     log->Printf ("Condition evaluated for breakpoint %s on thread 0x%llx conditon_says_stop: %i.",
506                                                  s.GetData(),
507                                                  static_cast<unsigned long long>(thread_sp->GetID()),
508                                                  condition_says_stop);
509                                 }
510                                 if (!condition_says_stop)
511                                 {
512                                     // We don't want to increment the hit count of breakpoints if the condition fails.
513                                     // We've already bumped it by the time we get here, so undo the bump:
514                                     bp_loc_sp->UndoBumpHitCount();
515                                     continue;
516                                 }
517                             }
518                         }
519 
520                         bool callback_says_stop;
521 
522                         // FIXME: For now the callbacks have to run in async mode - the first time we restart we need
523                         // to get out of there.  So set it here.
524                         // When we figure out how to nest breakpoint hits then this will change.
525 
526                         Debugger &debugger = thread_sp->CalculateTarget()->GetDebugger();
527                         bool old_async = debugger.GetAsyncExecution();
528                         debugger.SetAsyncExecution (true);
529 
530                         callback_says_stop = bp_loc_sp->InvokeCallback (&context);
531 
532                         debugger.SetAsyncExecution (old_async);
533 
534                         if (callback_says_stop)
535                             m_should_stop = true;
536 
537                         // If we are going to stop for this breakpoint, then remove the breakpoint.
538                         if (callback_says_stop && bp_loc_sp && bp_loc_sp->GetBreakpoint().IsOneShot())
539                         {
540                             thread_sp->GetProcess()->GetTarget().RemoveBreakpointByID (bp_loc_sp->GetBreakpoint().GetID());
541                         }
542 
543                         // Also make sure that the callback hasn't continued the target.
544                         // If it did, when we'll set m_should_start to false and get out of here.
545                         if (HasTargetRunSinceMe ())
546                         {
547                             m_should_stop = false;
548                             break;
549                         }
550                     }
551                 }
552                 // We've figured out what this stop wants to do, so mark it as valid so we don't compute it again.
553                 m_should_stop_is_valid = true;
554 
555             }
556             else
557             {
558                 m_should_stop = true;
559                 m_should_stop_is_valid = true;
560                 Log * log_process(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
561 
562                 if (log_process)
563                     log_process->Printf ("Process::%s could not find breakpoint site id: %" PRId64 "...", __FUNCTION__, m_value);
564             }
565             if (log)
566                 log->Printf ("Process::%s returning from action with m_should_stop: %d.", __FUNCTION__, m_should_stop);
567         }
568     }
569 
570 private:
571     std::string m_description;
572     bool m_should_stop;
573     bool m_should_stop_is_valid;
574     bool m_should_perform_action; // Since we are trying to preserve the "state" of the system even if we run functions
575                                   // etc. behind the users backs, we need to make sure we only REALLY perform the action once.
576     lldb::addr_t m_address;       // We use this to capture the breakpoint site address when we create the StopInfo,
577                                   // in case somebody deletes it between the time the StopInfo is made and the
578                                   // description is asked for.
579     lldb::break_id_t m_break_id;
580     bool m_was_one_shot;
581 };
582 
583 
584 //----------------------------------------------------------------------
585 // StopInfoWatchpoint
586 //----------------------------------------------------------------------
587 
588 class StopInfoWatchpoint : public StopInfo
589 {
590 public:
591     // Make sure watchpoint is properly disabled and subsequently enabled while performing watchpoint actions.
592     class WatchpointSentry {
593     public:
594         WatchpointSentry(Process *p, Watchpoint *w):
595             process(p),
596             watchpoint(w)
597         {
598             if (process && watchpoint)
599             {
600                 const bool notify = false;
601                 watchpoint->TurnOnEphemeralMode();
602                 process->DisableWatchpoint(watchpoint, notify);
603             }
604         }
605         ~WatchpointSentry()
606         {
607             if (process && watchpoint)
608             {
609                 if (!watchpoint->IsDisabledDuringEphemeralMode())
610                 {
611                     const bool notify = false;
612                     process->EnableWatchpoint(watchpoint, notify);
613                 }
614                 watchpoint->TurnOffEphemeralMode();
615             }
616         }
617     private:
618         Process *process;
619         Watchpoint *watchpoint;
620     };
621 
622     StopInfoWatchpoint (Thread &thread, break_id_t watch_id) :
623         StopInfo(thread, watch_id),
624         m_description(),
625         m_should_stop(false),
626         m_should_stop_is_valid(false)
627     {
628     }
629 
630     virtual ~StopInfoWatchpoint ()
631     {
632     }
633 
634     virtual StopReason
635     GetStopReason () const
636     {
637         return eStopReasonWatchpoint;
638     }
639 
640     virtual const char *
641     GetDescription ()
642     {
643         if (m_description.empty())
644         {
645             StreamString strm;
646             strm.Printf("watchpoint %" PRIi64, m_value);
647             m_description.swap (strm.GetString());
648         }
649         return m_description.c_str();
650     }
651 
652 protected:
653     virtual bool
654     ShouldStopSynchronous (Event *event_ptr)
655     {
656         // ShouldStop() method is idempotent and should not affect hit count.
657         // See Process::RunPrivateStateThread()->Process()->HandlePrivateEvent()
658         // -->Process()::ShouldBroadcastEvent()->ThreadList::ShouldStop()->
659         // Thread::ShouldStop()->ThreadPlanBase::ShouldStop()->
660         // StopInfoWatchpoint::ShouldStop() and
661         // Event::DoOnRemoval()->Process::ProcessEventData::DoOnRemoval()->
662         // StopInfoWatchpoint::PerformAction().
663         if (m_should_stop_is_valid)
664             return m_should_stop;
665 
666         ThreadSP thread_sp (m_thread_wp.lock());
667         if (thread_sp)
668         {
669             WatchpointSP wp_sp (thread_sp->CalculateTarget()->GetWatchpointList().FindByID(GetValue()));
670             if (wp_sp)
671             {
672                 // Check if we should stop at a watchpoint.
673                 ExecutionContext exe_ctx (thread_sp->GetStackFrameAtIndex(0));
674                 StoppointCallbackContext context (event_ptr, exe_ctx, true);
675                 m_should_stop = wp_sp->ShouldStop (&context);
676             }
677             else
678             {
679                 Log *log(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
680 
681                 if (log)
682                     log->Printf ("Process::%s could not find watchpoint location id: %" PRId64 "...",
683                                  __FUNCTION__, GetValue());
684 
685                 m_should_stop = true;
686             }
687         }
688         m_should_stop_is_valid = true;
689         return m_should_stop;
690     }
691 
692     bool
693     ShouldStop (Event *event_ptr)
694     {
695         // This just reports the work done by PerformAction or the synchronous stop.  It should
696         // only ever get called after they have had a chance to run.
697         assert (m_should_stop_is_valid);
698         return m_should_stop;
699     }
700 
701     virtual void
702     PerformAction (Event *event_ptr)
703     {
704         Log *log = lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_WATCHPOINTS);
705         // We're going to calculate if we should stop or not in some way during the course of
706         // this code.  Also by default we're going to stop, so set that here.
707         m_should_stop = true;
708 
709         ThreadSP thread_sp (m_thread_wp.lock());
710         if (thread_sp)
711         {
712 
713             WatchpointSP wp_sp (thread_sp->CalculateTarget()->GetWatchpointList().FindByID(GetValue()));
714             if (wp_sp)
715             {
716                 ExecutionContext exe_ctx (thread_sp->GetStackFrameAtIndex(0));
717                 Process* process = exe_ctx.GetProcessPtr();
718 
719                 // This sentry object makes sure the current watchpoint is disabled while performing watchpoint actions,
720                 // and it is then enabled after we are finished.
721                 WatchpointSentry sentry(process, wp_sp.get());
722 
723                 {
724                     // check if this process is running on an architecture where watchpoints trigger
725                     // before the associated instruction runs. if so, disable the WP, single-step and then
726                     // re-enable the watchpoint
727                     if (process)
728                     {
729                         uint32_t num;
730                         bool wp_triggers_after;
731                         if (process->GetWatchpointSupportInfo(num, wp_triggers_after).Success())
732                         {
733                             if (!wp_triggers_after)
734                             {
735                                 StopInfoSP stored_stop_info_sp = thread_sp->GetStopInfo();
736                                 assert (stored_stop_info_sp.get() == this);
737 
738                                 ThreadPlanSP new_plan_sp(thread_sp->QueueThreadPlanForStepSingleInstruction(false, // step-over
739                                                                                                             false,     // abort_other_plans
740                                                                                                             true));    // stop_other_threads
741                                 new_plan_sp->SetIsMasterPlan (true);
742                                 new_plan_sp->SetOkayToDiscard (false);
743                                 new_plan_sp->SetPrivate (true);
744                                 process->GetThreadList().SetSelectedThreadByID (thread_sp->GetID());
745                                 process->ResumeSynchronous(NULL);
746                                 process->GetThreadList().SetSelectedThreadByID (thread_sp->GetID());
747                                 thread_sp->SetStopInfo(stored_stop_info_sp);
748                             }
749                         }
750                     }
751                 }
752 
753                 if (m_should_stop && wp_sp->GetConditionText() != NULL)
754                 {
755                     // We need to make sure the user sees any parse errors in their condition, so we'll hook the
756                     // constructor errors up to the debugger's Async I/O.
757                     ExpressionResults result_code;
758                     EvaluateExpressionOptions expr_options;
759                     expr_options.SetUnwindOnError(true);
760                     expr_options.SetIgnoreBreakpoints(true);
761                     ValueObjectSP result_value_sp;
762                     Error error;
763                     result_code = ClangUserExpression::Evaluate (exe_ctx,
764                                                                  expr_options,
765                                                                  wp_sp->GetConditionText(),
766                                                                  NULL,
767                                                                  result_value_sp,
768                                                                  error);
769                     if (result_code == eExpressionCompleted)
770                     {
771                         if (result_value_sp)
772                         {
773                             Scalar scalar_value;
774                             if (result_value_sp->ResolveValue (scalar_value))
775                             {
776                                 if (scalar_value.ULongLong(1) == 0)
777                                 {
778                                     // We have been vetoed.  This takes precedence over querying
779                                     // the watchpoint whether it should stop (aka ignore count and
780                                     // friends).  See also StopInfoWatchpoint::ShouldStop() as well
781                                     // as Process::ProcessEventData::DoOnRemoval().
782                                     m_should_stop = false;
783                                 }
784                                 else
785                                     m_should_stop = true;
786                                 if (log)
787                                     log->Printf("Condition successfully evaluated, result is %s.\n",
788                                                 m_should_stop ? "true" : "false");
789                             }
790                             else
791                             {
792                                 m_should_stop = true;
793                                 if (log)
794                                     log->Printf("Failed to get an integer result from the expression.");
795                             }
796                         }
797                     }
798                     else
799                     {
800                         Debugger &debugger = exe_ctx.GetTargetRef().GetDebugger();
801                         StreamSP error_sp = debugger.GetAsyncErrorStream ();
802                         error_sp->Printf ("Stopped due to an error evaluating condition of watchpoint ");
803                         wp_sp->GetDescription (error_sp.get(), eDescriptionLevelBrief);
804                         error_sp->Printf (": \"%s\"",
805                                           wp_sp->GetConditionText());
806                         error_sp->EOL();
807                         const char *err_str = error.AsCString("<Unknown Error>");
808                         if (log)
809                             log->Printf("Error evaluating condition: \"%s\"\n", err_str);
810 
811                         error_sp->PutCString (err_str);
812                         error_sp->EOL();
813                         error_sp->Flush();
814                         // If the condition fails to be parsed or run, we should stop.
815                         m_should_stop = true;
816                     }
817                 }
818 
819                 // If the condition says to stop, we run the callback to further decide whether to stop.
820                 if (m_should_stop)
821                 {
822                     StoppointCallbackContext context (event_ptr, exe_ctx, false);
823                     bool stop_requested = wp_sp->InvokeCallback (&context);
824                     // Also make sure that the callback hasn't continued the target.
825                     // If it did, when we'll set m_should_stop to false and get out of here.
826                     if (HasTargetRunSinceMe ())
827                         m_should_stop = false;
828 
829                     if (m_should_stop && !stop_requested)
830                     {
831                         // We have been vetoed by the callback mechanism.
832                         m_should_stop = false;
833                     }
834                 }
835                 // Finally, if we are going to stop, print out the new & old values:
836                 if (m_should_stop)
837                 {
838                     wp_sp->CaptureWatchedValue(exe_ctx);
839 
840                     Debugger &debugger = exe_ctx.GetTargetRef().GetDebugger();
841                     StreamSP output_sp = debugger.GetAsyncOutputStream ();
842                     wp_sp->DumpSnapshots(output_sp.get());
843                     output_sp->EOL();
844                     output_sp->Flush();
845                 }
846 
847             }
848             else
849             {
850                 Log * log_process(lldb_private::GetLogIfAllCategoriesSet (LIBLLDB_LOG_PROCESS));
851 
852                 if (log_process)
853                     log_process->Printf ("Process::%s could not find watchpoint id: %" PRId64 "...", __FUNCTION__, m_value);
854             }
855             if (log)
856                 log->Printf ("Process::%s returning from action with m_should_stop: %d.", __FUNCTION__, m_should_stop);
857 
858             m_should_stop_is_valid = true;
859         }
860     }
861 
862 private:
863     std::string m_description;
864     bool m_should_stop;
865     bool m_should_stop_is_valid;
866 };
867 
868 
869 
870 //----------------------------------------------------------------------
871 // StopInfoUnixSignal
872 //----------------------------------------------------------------------
873 
874 class StopInfoUnixSignal : public StopInfo
875 {
876 public:
877 
878     StopInfoUnixSignal (Thread &thread, int signo) :
879         StopInfo (thread, signo)
880     {
881     }
882 
883     virtual ~StopInfoUnixSignal ()
884     {
885     }
886 
887 
888     virtual StopReason
889     GetStopReason () const
890     {
891         return eStopReasonSignal;
892     }
893 
894     virtual bool
895     ShouldStopSynchronous (Event *event_ptr)
896     {
897         ThreadSP thread_sp (m_thread_wp.lock());
898         if (thread_sp)
899             return thread_sp->GetProcess()->GetUnixSignals().GetShouldStop (m_value);
900         return false;
901     }
902 
903     virtual bool
904     ShouldStop (Event *event_ptr)
905     {
906         ThreadSP thread_sp (m_thread_wp.lock());
907         if (thread_sp)
908             return thread_sp->GetProcess()->GetUnixSignals().GetShouldStop (m_value);
909         return false;
910     }
911 
912 
913     // If should stop returns false, check if we should notify of this event
914     virtual bool
915     DoShouldNotify (Event *event_ptr)
916     {
917         ThreadSP thread_sp (m_thread_wp.lock());
918         if (thread_sp)
919         {
920             bool should_notify = thread_sp->GetProcess()->GetUnixSignals().GetShouldNotify (m_value);
921             if (should_notify)
922             {
923                 StreamString strm;
924                 strm.Printf ("thread %d received signal: %s",
925                              thread_sp->GetIndexID(),
926                              thread_sp->GetProcess()->GetUnixSignals().GetSignalAsCString (m_value));
927                 Process::ProcessEventData::AddRestartedReason(event_ptr, strm.GetData());
928             }
929             return should_notify;
930         }
931         return true;
932     }
933 
934 
935     virtual void
936     WillResume (lldb::StateType resume_state)
937     {
938         ThreadSP thread_sp (m_thread_wp.lock());
939         if (thread_sp)
940         {
941             if (thread_sp->GetProcess()->GetUnixSignals().GetShouldSuppress(m_value) == false)
942                 thread_sp->SetResumeSignal(m_value);
943         }
944     }
945 
946     virtual const char *
947     GetDescription ()
948     {
949         if (m_description.empty())
950         {
951             ThreadSP thread_sp (m_thread_wp.lock());
952             if (thread_sp)
953             {
954                 StreamString strm;
955                 const char *signal_name = thread_sp->GetProcess()->GetUnixSignals().GetSignalAsCString (m_value);
956                 if (signal_name)
957                     strm.Printf("signal %s", signal_name);
958                 else
959                     strm.Printf("signal %" PRIi64, m_value);
960                 m_description.swap (strm.GetString());
961             }
962         }
963         return m_description.c_str();
964     }
965 };
966 
967 //----------------------------------------------------------------------
968 // StopInfoTrace
969 //----------------------------------------------------------------------
970 
971 class StopInfoTrace : public StopInfo
972 {
973 public:
974 
975     StopInfoTrace (Thread &thread) :
976         StopInfo (thread, LLDB_INVALID_UID)
977     {
978     }
979 
980     virtual ~StopInfoTrace ()
981     {
982     }
983 
984     virtual StopReason
985     GetStopReason () const
986     {
987         return eStopReasonTrace;
988     }
989 
990     virtual const char *
991     GetDescription ()
992     {
993         if (m_description.empty())
994         return "trace";
995         else
996             return m_description.c_str();
997     }
998 };
999 
1000 
1001 //----------------------------------------------------------------------
1002 // StopInfoException
1003 //----------------------------------------------------------------------
1004 
1005 class StopInfoException : public StopInfo
1006 {
1007 public:
1008 
1009     StopInfoException (Thread &thread, const char *description) :
1010         StopInfo (thread, LLDB_INVALID_UID)
1011     {
1012         if (description)
1013             SetDescription (description);
1014     }
1015 
1016     virtual
1017     ~StopInfoException ()
1018     {
1019     }
1020 
1021     virtual StopReason
1022     GetStopReason () const
1023     {
1024         return eStopReasonException;
1025     }
1026 
1027     virtual const char *
1028     GetDescription ()
1029     {
1030         if (m_description.empty())
1031             return "exception";
1032         else
1033             return m_description.c_str();
1034     }
1035 };
1036 
1037 
1038 //----------------------------------------------------------------------
1039 // StopInfoThreadPlan
1040 //----------------------------------------------------------------------
1041 
1042 class StopInfoThreadPlan : public StopInfo
1043 {
1044 public:
1045 
1046     StopInfoThreadPlan (ThreadPlanSP &plan_sp, ValueObjectSP &return_valobj_sp, ClangExpressionVariableSP &expression_variable_sp) :
1047         StopInfo (plan_sp->GetThread(), LLDB_INVALID_UID),
1048         m_plan_sp (plan_sp),
1049         m_return_valobj_sp (return_valobj_sp),
1050         m_expression_variable_sp (expression_variable_sp)
1051     {
1052     }
1053 
1054     virtual ~StopInfoThreadPlan ()
1055     {
1056     }
1057 
1058     virtual StopReason
1059     GetStopReason () const
1060     {
1061         return eStopReasonPlanComplete;
1062     }
1063 
1064     virtual const char *
1065     GetDescription ()
1066     {
1067         if (m_description.empty())
1068         {
1069             StreamString strm;
1070             m_plan_sp->GetDescription (&strm, eDescriptionLevelBrief);
1071             m_description.swap (strm.GetString());
1072         }
1073         return m_description.c_str();
1074     }
1075 
1076     ValueObjectSP
1077     GetReturnValueObject()
1078     {
1079         return m_return_valobj_sp;
1080     }
1081 
1082     ClangExpressionVariableSP
1083     GetExpressionVariable()
1084     {
1085         return m_expression_variable_sp;
1086     }
1087 
1088 protected:
1089     virtual bool
1090     ShouldStop (Event *event_ptr)
1091     {
1092         if (m_plan_sp)
1093             return m_plan_sp->ShouldStop(event_ptr);
1094         else
1095             return StopInfo::ShouldStop(event_ptr);
1096     }
1097 
1098 private:
1099     ThreadPlanSP m_plan_sp;
1100     ValueObjectSP m_return_valobj_sp;
1101     ClangExpressionVariableSP m_expression_variable_sp;
1102 };
1103 
1104 class StopInfoExec : public StopInfo
1105 {
1106 public:
1107 
1108     StopInfoExec (Thread &thread) :
1109         StopInfo (thread, LLDB_INVALID_UID),
1110         m_performed_action (false)
1111     {
1112     }
1113 
1114     virtual
1115     ~StopInfoExec ()
1116     {
1117     }
1118 
1119     virtual StopReason
1120     GetStopReason () const
1121     {
1122         return eStopReasonExec;
1123     }
1124 
1125     virtual const char *
1126     GetDescription ()
1127     {
1128         return "exec";
1129     }
1130 protected:
1131 
1132     virtual void
1133     PerformAction (Event *event_ptr)
1134     {
1135         // Only perform the action once
1136         if (m_performed_action)
1137             return;
1138         m_performed_action = true;
1139         ThreadSP thread_sp (m_thread_wp.lock());
1140         if (thread_sp)
1141             thread_sp->GetProcess()->DidExec();
1142     }
1143 
1144     bool m_performed_action;
1145 };
1146 
1147 } // namespace lldb_private
1148 
1149 StopInfoSP
1150 StopInfo::CreateStopReasonWithBreakpointSiteID (Thread &thread, break_id_t break_id)
1151 {
1152     return StopInfoSP (new StopInfoBreakpoint (thread, break_id));
1153 }
1154 
1155 StopInfoSP
1156 StopInfo::CreateStopReasonWithBreakpointSiteID (Thread &thread, break_id_t break_id, bool should_stop)
1157 {
1158     return StopInfoSP (new StopInfoBreakpoint (thread, break_id, should_stop));
1159 }
1160 
1161 StopInfoSP
1162 StopInfo::CreateStopReasonWithWatchpointID (Thread &thread, break_id_t watch_id)
1163 {
1164     return StopInfoSP (new StopInfoWatchpoint (thread, watch_id));
1165 }
1166 
1167 StopInfoSP
1168 StopInfo::CreateStopReasonWithSignal (Thread &thread, int signo)
1169 {
1170     return StopInfoSP (new StopInfoUnixSignal (thread, signo));
1171 }
1172 
1173 StopInfoSP
1174 StopInfo::CreateStopReasonToTrace (Thread &thread)
1175 {
1176     return StopInfoSP (new StopInfoTrace (thread));
1177 }
1178 
1179 StopInfoSP
1180 StopInfo::CreateStopReasonWithPlan (ThreadPlanSP &plan_sp,
1181                                     ValueObjectSP return_valobj_sp,
1182                                     ClangExpressionVariableSP expression_variable_sp)
1183 {
1184     return StopInfoSP (new StopInfoThreadPlan (plan_sp, return_valobj_sp, expression_variable_sp));
1185 }
1186 
1187 StopInfoSP
1188 StopInfo::CreateStopReasonWithException (Thread &thread, const char *description)
1189 {
1190     return StopInfoSP (new StopInfoException (thread, description));
1191 }
1192 
1193 StopInfoSP
1194 StopInfo::CreateStopReasonWithExec (Thread &thread)
1195 {
1196     return StopInfoSP (new StopInfoExec (thread));
1197 }
1198 
1199 ValueObjectSP
1200 StopInfo::GetReturnValueObject(StopInfoSP &stop_info_sp)
1201 {
1202     if (stop_info_sp && stop_info_sp->GetStopReason() == eStopReasonPlanComplete)
1203     {
1204         StopInfoThreadPlan *plan_stop_info = static_cast<StopInfoThreadPlan *>(stop_info_sp.get());
1205         return plan_stop_info->GetReturnValueObject();
1206     }
1207     else
1208         return ValueObjectSP();
1209 }
1210 
1211 ClangExpressionVariableSP
1212 StopInfo::GetExpressionVariable(StopInfoSP &stop_info_sp)
1213 {
1214     if (stop_info_sp && stop_info_sp->GetStopReason() == eStopReasonPlanComplete)
1215     {
1216         StopInfoThreadPlan *plan_stop_info = static_cast<StopInfoThreadPlan *>(stop_info_sp.get());
1217         return plan_stop_info->GetExpressionVariable();
1218     }
1219     else
1220         return ClangExpressionVariableSP();
1221 }
1222